The United States Department of Homeland Security (DHS) will from now on routinely collect social media and other online information on immigrants to the United States, sparking fears of overly broad state surveillance.
Following a trial earlier this year, the DHS will now gather not just immigrants' social media handles and aliases, but also their web search histories and unspecified "associated identifiable information".
Collection of the data will also include details on individuals and organisations that the immigrants have interacted with online, including US and nationals of other countries.
The practice will start on October 17 US time, and is causing alarm among privacy and human rights advocates.
"This rule will have an extreme chilling effect on online speech. It effectively makes it impossible for immigrants to have pseudonymous internet identities, or to speak online without fear of government retribution," Nuala O'Connor, the chief executive of digital rights lobby group Centre for Democracy and Technology said.
CDT pointed out that the new rules enable the DHS to append data from commercial providers to the information collected.
This raises concerns about accuracy and accountability, CDT said.
The lobby group said mass collection of data was counterproductive as it does not lead to better or more actionable information, and simply creates more noise.
Bulk collection of online information from migrants by US authorities was mooted last year, and raised immediate protests from rights groups who said the measure would have a chilling effect on free speech, as well as being vague and overly broad.
Along with a range of other technological provisions such as biometric screening and collection of immigrant DNA, the collection of social media and online information is said to assist the US government in its efforts to prevent terrorist activity.